Hot spots are commonly referred to as acute moist dermatitis because it frequently occurs during the warm months of the year. The lesions are inflamed and hot to the touch. This disease is most commonly seen in breeds of dogs that have very dense, heavy coats, and it may be related to poor ventilation of the skin or improper grooming to remove matted hair and debris.
The lesions can develop in a matter of a few hours and are usually noticed as a patch of missing hair. A round, red, moist area that is extremely painful, rapidly develops. Self-trauma occurs in the form of biting and scratching because the lesions are intensely pruritic. This condition needs to be treated otherwise it can spread into other areas. Many conditions such as allergic reactions, external parasites, skin infections, an unhealed injury, or improper grooming can develop into a hot spot.
Diet may provide a role if it produces a severe fatty acid deficiency or if the pet has a food-induced allergy. Improperly formulated or improperly stored dry pet foods that are fed can lead to a fatty acid deficiency that is characterized by a number of dermatological signs. The most common underlying cause of acute dermatitis in dogs appears to be flea-bite hypersensitivity and other allergic skin conditions.